Refactor filename/directory in DICompileUnit into a DIFile

This is the next step towards making the metadata for DIScopes have a common
prefix rather than having to delegate based on their tag type.

llvm-svn: 176913
diff --git a/llvm/test/DebugInfo/2009-11-10-CurrentFn.ll b/llvm/test/DebugInfo/2009-11-10-CurrentFn.ll
index c196305..e862eb0 100644
--- a/llvm/test/DebugInfo/2009-11-10-CurrentFn.ll
+++ b/llvm/test/DebugInfo/2009-11-10-CurrentFn.ll
@@ -12,7 +12,7 @@
 
 !llvm.dbg.cu = !{!0}
 
-!0 = metadata !{i32 720913, i32 0, i32 12, metadata !"cf.c", metadata !"/private/tmp", metadata !"clang version 3.0 (trunk 139632)", i1 true, metadata !"", i32 0, metadata !1, metadata !1, metadata !3, metadata !1, metadata !""} ; [ DW_TAG_compile_unit ]
+!0 = metadata !{i32 720913, i32 0, i32 12, metadata !6, metadata !"clang version 3.0 (trunk 139632)", i1 true, metadata !"", i32 0, metadata !1, metadata !1, metadata !3, metadata !1, metadata !""} ; [ DW_TAG_compile_unit ]
 !1 = metadata !{i32 0}
 !3 = metadata !{metadata !5}
 !5 = metadata !{i32 720942, i32 0, metadata !6, metadata !"bar", metadata !"bar", metadata !"", metadata !6, i32 3, metadata !7, i1 false, i1 true, i32 0, i32 0, i32 0, i32 256, i1 true, void (i32)* @bar, null, null, metadata !9} ; [ DW_TAG_subprogram ]